The first order rate constant for the decomposition of dimethyl ether (CH3)2O--->CH4 + H2 + CO (reactant and products all in gas phase) is 3.2X10^-4/s at 450C. The reaction is carried out in a constant volume flask. Initially only dimethyl ether is present and the pressure is 0.350 atm. How can evaluate the pressure of the system after 8.0 min? Assume ideal behavior.